here's john boehner's pledge signed 20 years ago. if somebody signed this 10 years ago or 18 years ago, 20 years ago, are they still bound by it? >> now when you got married, did your wife understand there was an expiration date on that promise? when you borrowed money to buy your house, did you say, "oh geez, that mortgage? that was ten years ago. you're still asking me for money?" you know, if you make a commitment, you make a commitment. >> reporter: the pledge is the biggest obstacle to any deal that would raise taxes, but with a budget crisis on the horizon and a re-elected president insisting on tax increases, some republicans are now thinking the unthinkable, ditching the pledge. >> i will violate the pledge, long story short, for the good of the country. >> i'm not obligated on the pledge. >> the world has changed, and the economic situation is different. >> reporter: and while virtually every republican in the past signed it, nearly a third of the newly elected house republicans refused to sign it this time. republicans ditc